1,1

All terms are in A066940. The first member of A066940 not in this sequence is 61.

Robert Israel, Table of n, a(n) for n = 1..10000

a(n) = A000720(A275697(n+1)). - Robert Israel, May 31 2018

select(n -> nops(convert(ithprime(n+1)/ithprime(n), confrac))=3, [$1..1000]);

(PARI) isok(n) = length(contfrac(prime(n+1)/prime(n))) == 3; \\ Michel Marcus, May 31 2018

Cf. A000720, A066940, A071866, A275697. Contains A029707.

Sequence in context: A024899 A114518 A066940 * A100118 A295389 A028781

Adjacent sequences: A305315 A305316 A305317 * A305319 A305320 A305321

nonn

Robert Israel, May 29 2018

approved